Correcting disturbances on telephone and other like wires.



J. B. SPEED. CORRECTING DISTURBANGES 0N TELEPHONE AND OTHER LIKE WIRES.APPLICATION. FILED. MARKS, 1 914. RENEWED SEPT. 10, 1914.

1,114,408. Patented 001;. 20, 1911 PATENT OFFICE.

UNITED STATES JAMES BUCKNEB sriann, or New YORK, N. Y.

1,114,408. Continuation of application Serial 110.725.3136,

Specification of Letters Patent.

Patented Oct. 20, 1914.

filed October 29,1912. This application filed March 3,1914,

.serial No. 822,128. Renewed September 10, 1914. Serial No. 861,135.

To all whom it may concern ,Be it known that I, JAMES BUOKNER SPEED, ofthe city, county, and State of New 'York, have invented a certain newand useful Improvement in Correcting Disturbances on Telephone and otherlike Wires, of which the following is a specification.

Except as to certain details of circuit a1- rangement in thetransformers 11-12, including theimpedance coils 16, this application isa continuation of my application 728,336, filed Oct.v 29, 1912, and issubstituted therefor.

My invention relates to the art of correcting disturbances on telephoneand other like wires, occasioned by the proximity of electric powercircuits.

It consists, more essentially, in separately correcting the fundamentalfrequency, and its harmonics, of the disturbing current by theapplication of independent currents possessing characteristics similarto said components of the disturbing current.

The particular method of procedure which I have chosen to hereinafterdescribe in detail comprises the steps of producing an observablemanifestation of the disturbance on the telephone line; producing asecond disturbance on saidline synthetically out of alternating currentswhose periodicities are those of the fundamental and of the harmonics ofthe disturbance note; and reg: ulating and adjusting the several partsof said synthetically constructed disturbance by reference to the saidobservable manifestation until said disturbance is as nearly nullifiedas desired. These several steps of my method are capable of andsubjected to refinements and qualifications which while not changing oraffecting the generic idea of my method render the invention ofpractical moment, and in themselves lend further novelty to the method;as, for example, the best form in which to produce the observablemanifestation of the disturbance to be corrected in order that it may bepractically followed and serve as a guide in the adjustment andattainment of the similar and opposite neutralizing disturbance; and inthe best manufacture, as it were, and control of said neutralizingdisturbance in order that it may be rendered practical in the attainmentof its object.

In order to fully understand my inven- 1 tion,I-illustratediagrammatically in the accompanymg drawings an apparatus bythe use of whlch the method may be carried out.

In these drawings Figure 1 is a diagram of the apparatus abovementioned. Fig. 2 1s a plan view enlarged of the reflecting disk.

1 1s a telephone'or telegraph line in which by reason of the proximityof an electric power line 2 disturbances or troubles occur.

A indicates, as a whole, an oscilloscope by which the disturbances inthe line 1. are made visually manifest. Though this mani festation maybe of any suitable observable character, I recommend, in practice, aform of oscilloscope which will give a closed curve or polar type ofdiagram, in which one revolution,or 360 degrees, of the diagram occupiesthe period of one cycle of the fundamental of the disturbance. It is,further, best that'the visual representation of the disturbance shall bestationary in azimuth, as this is desirable for the correction ofdisturbances resulting from more than one source of power not operatedin parallel with the others.

In general; the oscilloscope A comprises a source of light 3, say asmall electric bulb. A minute iron disk 4 is pivoted in gimbals 5, so asto be free to turn in any direction, except in azimuth, said diskcarrying a small concave mirror or a reflecting surface 6. This disk isheld in the plane of its gimbal rings by a magneticfield produced by thesix pole field magnet 7, the axis of said magnetic field being in theplane of the disk, and said magnetic field rotates synchronously withthe fundamental of the disturbance, by reason of being energized bythree 3-phase circuits, as shown.

A coil of wire 8 is arranged with its axis perpendicular to the plane ofrotation of the magnetic field, and this coil of wire is connected inany suitable manner, as, for example, looped in, with the line wire 1,as shown, or a repeating coil may be used in the usual manner, so that.said coil is energized by the currents in said line wire. The coil ofwire 8 is so disposed with reference to the iron disk 4 and thefieldmagnet 7 that its effect is to displace the plane of tricallyconnected with the power wire 2 through the transformer at T, that is tosay, it is energized from the same power system which is the cause ofthe disturbance on the line wire 1. It will now readily be understoodthat because said field magnet 7 is energized from the power wire 2, itfollows that the movements of the iron disk l and its mirror 6 willalways occur at the same position in the circular path of the spot oflight, and, therefore, the same diagram will be repeated as many times asecond as-the frequency of the fundamental of the power circuit, andconsequently the disturbance. In order to observe this diagram, the beamof light from the bulb 3 is reflected by the mirror 6 to a ground glassscreen 9, and on this screen the spot of light will only retraverse thatportion of its path which is produced by the same source of disturbanceas is operating the rotating field. As this is the case, it follows thatthe vibrations introduced by the telephone conversation, or, in case ofa telegraph wire, by the application of the line battery by theoperators key, while interrupting or adding other vibrations to thedisturbance vibrations, will be practically invisible on the screen 9,since they are not repeated over and over again as are thosedisplacements produced by the disturbing current, which as beforestated, is operating the field magnet 7. Thus, by means of anoscilloscope, an observable manifestation of all the electricaldisturbance on the line is produced, Whether caused by electro-magneticor electrostatic or leakage or atmospheric conduction, saidmanifestation being a visual one and its diagram being a closed curve asits best type.

To carry out the second step of my method, namely, the production ofanother or second disturbance, and to realize the succeeding step,namely, the adjustment of this second disturbance in the light of thefirst visible diagram, in .such manner that it shall nullify thedisturbance which it is wished to correct, many ways and divers meansmay be adopted. Inasmuch as my present application for patent isdirected solely to the method of, and not to the means for, correctingthe disturbances stated, I have herein illustrated but one way and meansfor carrying out these steps, and that only in detail sufiicient for thepurpose of understanding the matter.

10 are field magnets. There is a plurality of these field magnets, andthough almost mechanically stationary, they, by the use of 3-phasecurrents, produce rotating magnetic fields, and these field magnets aremade so as to be manually shiftable around their axis of symmetrythrough a rotational angle less than 360 degrees. Corresponding to eachof these field magnets are armatures 11 Wound for single, three, five,seven, ete.,

phase circuits-only the single, three phase and five phase armaturesbeing shown, and these armatures are preferably so arranged that theymay he slid or pulled away in the direction of the axis of the field, soas to change the intensity of the poly-phase currents developed in themby the said field.

12 indicates a plurality of small transformers. There are as many ofthem as there are pairs of fields 10 and armatures 11, except that thefield magnets 10 and armatures 11 which are arranged for the productionof the fundamental frequency, do not require a transformer 12. The leads13 from the armatures 11 are carried to these transformers through thechoking coils 16 as shown, so that the fundamental frequency of thevarious members of each polyphase set neutralize each other and nothingis left in the secondary of the transformers except the electromotiveforce or current which is the same multiple of the fundamental as thenumber of phases brought into the transformer; for example, from thatarmature which is wound with three coils for threephase current, nothingwill come out of the transformer into which these armature leads aretaken except triple frequency.

I have'stated that the field magnets 10 are shiftable around their axisof symmetry, and also that their armatures are movable parallel tothemselves in the direction of the said axis. It now follows that byreason of the plurality of fields, it is possible to pro duce any of thesaid multiples of the frequency of the fundamental of the power which isoperating said fields, and further that by reason of the mechanicalrotative shiftability of said field magnet, each of such frequencies maybe varied independently as to phase, and, finally, that by reason of theadjustability of the armatures in the direction of the axis of symmetry,each of said currents may be varied independently as to intensity. Inthe present illustration the meansfor effecting these variationscomprise a crank handle 14 by which the field magnets 10 are rotativelyshifted, and slidmg bases 15 on which the armatures move to and from thefields. One of these groups of field magnets, armatures and transformersis connected up in that part of the complex generating set which isintended to give the variation of phase and intensity of the fundamentalof the correction current to be produced. Thus this group puts in thecontrol of the operator the means of varying the phase and intensity ofthe fundamental component of the complex correction wave or ,current tobe produced. The other succes" sive groups, of which there may be any required number, vary the phase and intensity of the difierent multiplesof the fundamental. It will now be seen that means are illustrated bythe operation of which a second I said second disturbance may l ef-149 Ithe line and be manipulated, and so controlledand adjusted as todisturbance may becreated on attain a complexity and character adaptingit to neutralize the first disturbance. This final step is efi'ected bythe operator through her deliberate selection and manipulation of theseveral adjusting devices of the groups of field magnets 10 andarmatures 11 to the end that in producing the complex correctioncurrent, she shall so manufacture itthat,

as will be indicated by its effect upon the visual diagram of thedisturbance to be cordesk, with a girl operator board, which rected, it1s equal to instant to said disturbance, thereby neutral izing it. Thiswill be better understood by abrief recital cf the manner of practicallycarrying out my method in a telephone exi change.

In any telephone exchange of moderate size there will be found a chiefoperators desk and a trouble clerks desk, etc., in addition to thenumerous panels of the large switchboard which are attendedon by theoperators. I propose to put in another desk, similar in generalappearance to the chief operators desk, to be called the Correction incharge. This desk may keep a hundred lines or more corrected. Itsoperation is similar to the chief operato-rs desk, in that the mainswitchboard girls or operators may all speak to the correction desk andplug any one of their noisy lines in connection with the correctiondesk. The correction operator on receiving a disturbed line from themain switchboard operator, will plug it into a hole of her correctionunits, of which there are about a hundred in her desk. This correctionunit contains, in some form, all of the apparatus heretofore described,or its. equivalents-that is, the oscilloscope and the complex frethequency generating groups or sets. As soon as she has plugged the line tothe correction unit, there will appear, on the ground glass screen, aclover-leaf-shaped figure, that is, one having three principal lobes andcusps, because usually the principal disturbance on telephone lines isof triple the frequency of the fundamental of the power lines. If,instead of a clover-leaf figure, a heart-shaped figure with one cusp isseen, this will indicate that the trouble is principally of thefundamental frequency. As a matter of fact, neither of these two figuresin its simplest form would ever occur, the outline of figure beingdecidedly wavy. Suppose, however, the figure contains one principaldent, indicating the presence of some of the fundamental in thedisturbance. Thereupon the operator reaches for that group of fieldmagnets 10 and armatures 11 which concerns the production of thefundamental of the correction current, and by moving the field pr iparound eng l tlb moving and opposite at every communicates with one ofthe re e i e ys w l aus h o de tin t e diagram; t o,b. 1m asse wh le. bythe armature she wlll change the magnitude-of the dent in the diagram asmeasured radially from its eometr cal center. This manipulation wilresult in the obliteration of any clearly distinguishable onesidednessinthe diagram. ,What remains in the diagram will then be very much morenoticeably .threersided or clover-leaf like. She now selects anothergrou of the com- .plex correction current set an by operating either thefield orthe armature (it makesno difierence on which she begins), shewill either shiftrotationally the three-sided cusps of the oscilloscopefigure, or else she will change the magnitude of the three-sided part,as measured radially from the center. Between the two Shiftings she thenobliterates the three-parted irregularity in her diagram. Frequently,this will be quite enough to bring the diagram of the. oscilloscope toindicate practical silence, but in cases where the circuit is of moreimportance. and greater silence is required, it may be desirable tocorrect in a similar manner the higher harmonics, a result attained byoperating other groups of the correction current set.

I claim:

1. The method of correcting alternating current disturbances ontelephone and other like wires which consists. in producing anobservable manifestation of the disturbance on the line; producing 'asecond disturbance on said line synthetically out of alternatingcurrents Whose periodicities are those of the fundamental and of theharmonics of the disturbance note; and regulating and adjusting theseveral parts of said synthetically constructed disturbance by referenceto the said observable manifestation until said disturbance is as nearlynullified as desired.

e th loo 2. The method of correcting alternating current disturbances ontelephone and other like wires which consists in producing an observablemanifestation of the disturbance on the line; producing a seconddisturbance on said line, part by part, of alternating currents of. thesame periodicities as the.

fundamental and the harmonics of the said disturbances; and, one by oneregulating and adjusting the said parts individually in phase andintensity, until, part by part. the disturbance has been neutralized,all

under the guidance of the said observable manifestation.

3. The method of correcting alternating current disturbances ontelephone and other like wires which consists in producing a visiblediagram of the disturbance on the line; producing a second disturbanceon said line synthetically out of alternating ourrentswhoseperiodicities are those of the fundamental and of the harmonics ofthe disturbance note; and regulatin and adjusting the several parts ofsai synthetically constructed disturbance by reference to the saidvisible diagram, until said disturbance is as nearly nullified asdesired.

4. The method of correcting alternating current disturbances 'on'telephone and other like wires which consists in producing a visiblediagram of the disturbance on the line; producing a second disturbanceon said line, part by part, of alternating currents of the sameperiodicities as the fundamental and the harmonics of the saiddisturbance; and, one by one, regulating and adjusting the said partsindividually in phase and in tensity, until, part by part, thedisturbance has been neutralized, all 'under the guidance of the saidvisible diagram.

5. The method of correcting alternating current disturbances ontelephone and other like wires which consists in producing a visiblediagram of the disturbance current on the line in such a way that thecyclical representation of the current is synchronous with thefundamental frequency of the disturbance, producing a second disturbanceon said line synthetically out of a plurality of alternating currentswhose periodicities are respectively that of the fundamental and of theseveral harmonics of the said disturbance; and so regulating andindividually adjustin the phases and -intensities of the said undamentaland the said harmonics, under the guidance furnished by "observation ofthe visible diagram of the first disturbance, that the seconddisturbance shall be at every instant equal and opposite to the firstdisturbance.

.6. The method of correcting disturbance heard in a telephone receiverwhich is connected with a telephone line exposed to the influence of analternating power circuit, which consists in separately-correcting thefundamental of the disturbance note and the several higher harmonics,each individually by the application 'of other alternating electromotiveforces of the same periodicity as the said fundamental and severalharmonies, said electromotive forces bein independently adjustable inphase an intensity so that the several partsinto which the disturbancetone is resolvable are attacked individually and nullifiedindividually,the adjustments being made by the operator under the guidance of anobservable manifestation of the amount of disturbance residual in thetelephone as the sec cessive steps of the nullification proceed.

7. The method of neutralizing disturbances in a signaling circuitexposed to the influence of an alternating current which consists inseparately neutralizing the fun- .damental frequency, and harmonics, ofthe disturbing current by the application of independent alternatingcurrents possessing characteristics similar to said components of thedisturbing current.

In testimony whereof I afiix my signature in presence of two witnesses.

' JAMES BUOKNER SPEED.

Witnesses:

' MARCELLUS BAILEY,

H. B. MARSTON.

